An NC hole-machining programming device disclosed in Japanese Laid-Open Patent Publication 170692/1994 detects a chamfering shape included in the hole-machining forms from CAD data, and determines a hole machining method based on the detected chamfering shape. The above publication describes that a hole machining method is selected according to data indicating internal diameter and depth of a hole, and the chamfered shape formed on the opening edge of the hole, included in the CAD data of hole-machining forms. For instance, drilling is selected as a machining method for a hole with no chamfer, and drilling and reaming is selected for a hole with a chamfer. Then, a tool type, a drill or a reamer, is determined in accordance with the selected hole machining method.
Since conventional NC hole-machining programming device selects a hole machining method based on a chamfer and a chamfering angle, they are not capable of handling various types of hole machining such as tapping or complicated hole-machining forms.
The present invention has been made to solve above problems. A first object of this invention is to provide an NC hole-machining programming device that can deal with various hole machining such as tapping and stepped-hole machining, as well as drilling or reaming.
A second object of the invention is to provide an NC hole-machining programming device that can deal with complicated hole-machining forms.